The general aim of this work is to develop new concepts and techniques which will lead to an understanding of the basic problem in photobiology: how the energy of light is efficiently converted into chemical or electrical energy across the basic biological structure, the membrane. The lipid bilayer is a good model of biological membranes and we have observed photo-initiated charge-transfer across these bilayer interfaces. The kinetics of these photoreactions are powerful probes of the previously inaccessible region of a few angstroms at this interface. The smallness of this region belies its importance throughout biology, from cell recognition and membrane fusion to nerve impulses. We attempt to understand this critical region by studying the effect of parameters such as ionic charge, ionic strength, structure of pigment and lipid on the kinetics of these laser stimulated reactions. This research also opens up the sub-microsecond time range to membrane studies. The same method is used to study proton transfer and thus the function of membrane-bound proteins such as rhodopsin and bacteriorhodopsin.